The present invention relates to an endoscopic hood which is attached to a distal end of an insertion section of an endoscope and, when the endoscope is inserted into a body cavity of a patient, protects the forward end portion of an insertion section of the endoscope.
Generally, upon an examination and surgery under an endoscope, a treating tool is used which is inserted into a body cavity of a patient via a tool insertion channel of the endoscope. As the treating tool for an endoscope there is a treating tool of such a type as to grasp a living tissue, such as a clipping device, a high frequency snare, grasping forceps as well as a biopsy forceps.
When the grasping or clipping procedure is performed with the use of this type of treating tool, the endoscope itself or the treating tool itself is moved or rotated, so that the distal end of the treating tool is so operated as to be directed toward a desired direction. And such procedure is performed to fix the tool to a given position with the distal end of the treating tool oriented toward a desired direction. For this reason, for the treating tool for grasping or clipping a living tissue it is important to set a direction in which the living tissue is grasped or clipped.
For example, Jpn. Pat. Appln. KOKAI Publication Nos. 8-131397 and 9-66019 disclose a structure in which, upon examination and surgery under an endoscope, an endoscopic hood of a substantially cylindrical configuration is detachably mounted to the distal end of the insertion section of the endoscope. In this case, the treating tool inserted into an inside of a body of a patient via a tool insertion channel of an endoscope is projected toward a front direction from the distal end of an endoscopic hood.
Further, the inner surface of the endoscopic hood of a conventional structure is formed to have a substantially smooth wall surface. For this reason, the treating tool slips upon being contacted with the inner wall surface of the endoscopic hood and is retained in a state to be freely rotatable about an axial direction of the insertion section of the endoscope. Even if, therefore, the distal end of the treating tool is correctly oriented toward a desired direction, the endoscope itself may be rotated, or the treating tool may be rotated about an axial direction of the insertion section of the endoscope, due to an action of an operation force upon the treating tool when the living tissue is grasped or clipped by the treating tool. In this situation, the distal end of the treating tool cannot be correctly retained toward an intended direction. For this reason, it takes a lot of time to fixedly orient the distal end of the treating tool toward the desired direction and it also takes a lot of a skill to perform such an operation.
It is accordingly an object of the present invention to provide an endoscopic hood which can restrict the distal end of a treating tool from being rotated about its axial direction and orient the tool toward a desired direction and do this treating procedure quickly and accurately.
In order to achieve the above-mentioned object of the present invention, the invention of claim 1 provides an endoscopic hood having a substantially cylindrical cap attached to a distal end of an insertion section of an endoscope to protect the distal end of an insertion section of the endoscope, the cap having a rotation restricting section in its inner surface which, when a treating tool is projected from the distal end of the insertion section of the endoscope, abuts against the treating tool to restrict the treating tool from being rotated about an axial direction of the insertion section of the endoscope.
According to the invention of claim 1, the treating tool projected from the distal end of the insertion section of the endoscope is set in abutting engagement with the rotation restricting section of the inner surface of the cap attached to the distal end of the endoscope. By doing so, the treating tool is restricted from being rotated about the axial direction of the insertion section of the endoscope. Further, after inserting the endoscope into a body cavity of a patient, the distal end of the treating tool held within the cap is projected onto a living tissue or, with the living tissue drawn into the cap, the distal end of the treating tool is abutted against the living tissue and the tool grasps or clips the living tissue.
According to the present invention, therefore, the distal end of the treating tool is initially restricted from being rotated about the axial direction and can be correctly oriented toward a desired direction, so that it is possible to perform a correct treatment quickly.
The invention of claim 2 is such that, in the endoscopic hood of claim 1, the rotation restricting section is comprised of a projection projected toward an inner direction on the inner surface of the cap.
According to the invention of claim 2, the treating tool projected from the distal end of the insertion section of the endoscope is set in abutting engagement with the projection of the rotation restricting section of the inner surface of the cap attached to the distal end of the insertion section of the endoscope. By doing so, the treating tool is restricted from being rotated about the axial direction of the insertion section of the endoscope.
The invention of claim 3 is such that, in the endoscopic hood of claim 2, the projection is comprised of a planar surface with a portion of the inner wall surface of the cap raised toward a center direction.
According to the invention of claim 3, the treating tool projected from the distal end of the insertion section of the endoscope is set in abutting engagement with the projection of the rotation restricting section which is raised toward the center direction at a portion of the inner wall surface of the cap attached to the distal end of the insertion section of the endoscope. By doing so, the treating tool is restricted from being rotated about the axial direction of the insertion section of the endoscope.
The invention of claim 4 is such that, in the endoscopic hood of claim 1, the rotation restricting section is comprised of a wall groove section provided by cutting the wall of the cap from an inner wall surface side to an outer wall surface side.
The invention of claim 4 is such that the treating tool projected from the distal end of the insertion section of the endoscope is set into abutting engagement with the wall groove section of the rotation restricting section provided by cutting the wall of the cap from an inner wall surface side to an outer wall surface side, the cap being attached to the distal end portion of the insertion section of the endoscope. By doing so, the treating tool is restricted from being rotated about the axial direction of the insertion section of the endoscope.
The invention of claim 5 is such that, in the endoscopic hood of claim 1, the cap is made of a hard material and has a fixing cylindrical body for fixing the distal end portion of the insertion section of the endoscope to an outer peripheral surface of a proximal end side thereof.
According to the invention of claim 5, the fixing cylindrical body at the outer peripheral surface of the proximal end side of the cap made of the hard material is fixed to the distal end portion of the insertion section of the endoscope. By doing so, the hard cap is attached to the distal end portion of the insertion section of the endoscope.
The invention of claim 6 is directed to a method of using an endoscopic hood which has a substantially cylindrical cap fixed to an endoscope, the cap being attached to a distal end portion of the insertion section of the endoscope to protect the distal end portion of the insertion section of the endoscope. In the method, the cap has a rotation restricting section at an inner wall surface thereof which is set in abutting contact with a treating tool when the treating tool is projected from the distal end of the insertion section of the endoscope, and restricts the treating tool from being rotated about an axial direction of the insertion section of the endoscope. The cap is so attached to align a line, which is drawn from a center of the distal end of the endoscope to a center of a channel, with a line which is drawn in a manner to set a cross-sectional configuration of the cap in a mirror image relation.
The invention of claim 7 is such that, in the method for using an endoscopic hood of claim 6, when the cap is used, the distal end of the treating tool is opened in a mutually opposite directions to restrict a rotation of the distal end of the treating tool.